In the above cited U.S. Pat. No. 4,445,376, a method and apparatus for measuring the specific force vector and angular rate vector of a moving body by means of a plurality of cyclically driven accelerometers is disclosed. The co-pending patent application Ser. No. 737,919 cited above discloses similar techniques for measuring the specific force vector and angular rate vector of a moving body utilizing either a single or a pair of accelerometers vibrating at a constant frequency. In the embodiments of the paired accelerometer rate and force sensors disclosed in the above patent application, the masses of the accelerometers are balanced with respect to rectolinear translation. This means that the pairs of accelerometers can be attached to a mounting frame work without causing any vibrational translation of the center of mass. However, the accelerometer configurations disclosed in the above patent application will produce angular vibration of any mass to which they are attached about the center of that mass.
As might be expected, it is important in many systems such as in inertial navigation systems to reduce to a minimum any vibration, be it linear or angular, that could affect the system. For example, in inertial navigation systems it is important to minimize the effects of one sensor on the performance of other sensors in the navigation system.